System, Components, and Methods for Detecting Moisture

ABSTRACT

To address this and/or other needs, the present inventor devised, among other things, a passive moisture detection probe that can be installed and left in place to continuously indicate whether the moisture-content in the wall-cavity of a building is below or above a desirable level. One exemplary moisture detection assembly includes a moisture-absorbent sensor element and an indicator. The sensor element, which can be placed in contact with the inner surface of a home&#39;s exterior sheathing, expands and contracts in response to the moisture content of the sheathing. The indicator, for example a rod, moves in responsive to the expansion and contraction of the sensor element, with its relative position corresponding to the moisture in the exterior sheathing and thus providing an on-going and observable sign of moisture intrusion.

RELATED APPLICATION

The present application claims priority to U.S. Provisional PatentApplication 61/660,879, which is incorporated herein by reference in itsentirety.

COPYRIGHT NOTICE AND PERMISSION

A portion of this patent document contains material subject to copyrightprotection. The copyright owner has no objection to the facsimilereproduction by anyone of the patent document or the patent disclosure,as it appears in the Patent and Trademark Office patent files orrecords, but otherwise reserves all copyrights whatsoever. The followingnotice applies to this document: Copyright © 2012, Alan B. Powell

TECHNICAL FIELD

Various embodiments of the present invention concern moisture detectionand indication devices, particularly those suitable for use inbuildings.

BACKGROUND

We have a love-hate relationship with water. We love it when it's wherewe need it to be, doing what we need it to do. And we hate it when it'snot. The truth of this is readily known around the world by homeownerswho have endured the expense, hassle, and sometimes life-threateningconsequences of water intrusion into their homes, not only in the highlyvisible and unescapable form of seasonal flooding, but also in theelusive, often invisible form of moisture intrusion. Which can remaininvisible for years until the serious damage of lost structuralintegrity or mold growth manifest.

For most stick-frame homes, the type most common in the United Statesand Canada, moisture intrusions typically occur in their wall cavities,the six-inch-thick insulation-filled space between a home's exteriorsiding and its interior sheetrock. The wood structure and insulation inthis wall cavity can act like a large sponge, with outward signs ofmoisture buildup only becoming visible when the cavity is saturated andthe problem is serious.

Moisture testing of all types of homes, especially stucco homes, is thebest way to minimize the risk of water damage and to identify problemsbefore they become serious. Typical testing methods require experts tomeasure the moisture content in the wall cavities of a home. Generally,this entails drilling holes in the home's exterior siding or interiorsheetrock, inserting highly sensitive electronic moisture meters intoits wall cavities. Readings from the moisture meters are then recordedand the holes refilled with caulk or spackle.

The present inventor has identified at least two problems with this formof testing. The first is that the testing is generally performed onlywhen signs of damage are already being noticed or when a home is on themarket, meaning not only that most detected intrusions could have beendetected and treated much earlier, but also that homeowners could havesaved thousands of dollars in repair expenses. The second problem isthat regular testing requires repeated drillings, probings, andrefillings. This level of professional effort using expensive measuringinstruments puts testing at a price point that many homeowners view astoo expensive to perform regularly.

Accordingly, the present inventor has identified a need for better waysof testing for moisture in buildings.

SUMMARY

To address this and/or other needs, the present inventor devised, amongother things, a passive moisture detection probe that can be installedand left in place to continuously indicate whether the moisture-contentin the wall-cavity of a building is below or above a desirable level.One exemplary moisture detection assembly includes a moisture-absorbentsensor element and an indicator. The sensor element, which can be placedin contact with the inner surface of a home's exterior sheathing,expands and contracts in response to the moisture content of thesheathing. The indicator, for example a rod, moves in responsive to theexpansion and contraction of the sensor element, with its relativeposition corresponding to the moisture in the exterior sheathing andthus providing an on-going and observable sign of moisture intrusion.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a center cross-sectional view of an exemplary moisturedetection assembly, which corresponds to one or more embodiments of thepresent invention.

FIG. 2 is an end view of the assembly in FIG. 1, corresponding to one ormore embodiments of the present invention.

FIG. 3 is a top plan view of an exemplary wingnut-style driver tool foruse in installing and/or removing the FIG. 1 assembly, corresponding toone or more embodiments of the present invention.

FIG. 4 is a profile view of the exemplary wingnut-style driver tool inFIG. 3, corresponding to one or more embodiments of the invention.

FIG. 5 is a profile view of the wingnut-style driver tool in FIGS. 3 and5, corresponding to one or more embodiments of the invention.

FIG. 6 is a center cross-sectional view of an exemplary drywall boretool for use in creating the FIG. 1 assembly, corresponding to one ormore embodiments of the invention.

FIG. 7 is a schematic diagram of an exemplary kit corresponding to oneor more embodiments of the present invention.

FIG. 8 is a center cross-sectional view of another exemplary moisturedetection assembly, which corresponds to one or more embodiments of thepresent invention.

FIG. 9 is an exploded isometric view of the FIG. 8 moisture detectionassembly and thus corresponds to one or more embodiments of the presentinvention.

FIG. 10 is an alternative form of a guide tube portion of the FIG. 8moisture detection assembly, which corresponds to one or moreembodiments of the present invention.

FIG. 11 is a front perspective view of an alternative drywall bore tool,which may be used in place of the FIG. 6 bore tool, and whichcorresponds to one or more embodiments of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

This document, which incorporates the drawings and the appended claims,describes one or more specific embodiments of one or more inventions.These embodiments, offered not to limit but only to exemplify and teachthe invention, are shown and described in sufficient detail to enablethose skilled in the art to implement or practice the invention(s).Thus, where appropriate to avoid obscuring the invention(s), thedescription may omit certain information known to those of skill in theart.

FIG. 1 shows cross-sectional view of a passive mechanical moisturedetection assembly. The assembly includes an exterior wood sheathing 101and an interior drywall or sheetrock 102, with sheathing 101 having aninterior sheathing surface 101A and drywall having a bore hole 102A.(Although not shown for sake of clarity, the space between the sheathingand drywall is understood to include some form of insulation, such as afiberglass insulation.) Inserted through bore hole 102A is an exemplarymoisture detection probe assembly 100.

Probe assembly 100 includes a probe body 110, an indicator rod 120, aspring bias element 130, a moisture sensor element 140, and an end cap150.

Probe body 110, which takes the exemplary form of a right circularcylindrical tube formed of machined, 3-D printed, injection-molded orcast-molded PVC or other durable plastic, includes a sheathing endportion 111, a drywall end portion 112, an exterior surface 113, aninterior axial passage or bore 114. (Drywall and sheathing sidemodifiers are used as directional cues to facilitate reference tospecific portions of other parts and components in this description,without necessarily using reference numbers for those specific portions.For example, indicator rod 120 has a drywall end portion, i.e. endclosest to the drywall, and a sheathing end closest to the sheathing.)At the drywall end portion 112, exterior surface 113 includes integrallyformed screw threads 113A which engage with drywall 102, specificallythe interior surface of bore hole 102A. Axial bore 114, which extendsthe entire length of the probe body from the drywall end portion to thesheathing end portion, includes a first diameter region 114A and seconddiameter region 114C that has a smaller diameter than region 114A todefine an annular ledge or step 114C. The smaller diameter of region114C can be defined as integral dimensional change within bore 114 or byinsertion of a separate right cylindrical tube within the probe body.Positioned within axial bore 114 is indicator rod 120.

Indicator rod 120, which is also form of a machined, 3-D printed, orinjection-molded or cast-molded PVC or other durable plastic, includesan elongated body portion 121 and a plunger head portion 122. Elongatedbody portion 121 and plunger head portion 122 both take the exemplaryform of a right circular cylinder, with body portion 121 beingsubstantially longer and having a smaller diameter than plunger headportion 122. Plunger head portion 122 is larger in diameter than seconddiameter region 114C, so that annular ledge 114C limits axial travel ormovement the indicator rod in a direction toward drywall end portion112. Plunger head portion 122 has a sheathing side and an opposingdrywall side that is integral with the elongated body portion 121extending through spring bias element 130.

Spring bias element 130, which in the exemplary embodiment takes theform of a helical spring, has respective first and second ends 131 and132. First end 131 is seated against annular ledge 114C, and second end132 is seated against a drywall side of plunger head portion 122,thereby biasing the adjacent sensor element 140 into contact withinterior sheathing surface 101A.

Sensor element 140, which for example takes the form a right cylindricalplug, includes a water-absorbent (more generally liquid-absorbing)material composition, which not only absorbs water but expands in sizeat least laterally or axially (along the lengthwise dimension of theindicator rod) during absorption. In the exemplary embodiment, thesensor element consists essentially of Hydrospan 100 material, acommercially available material composition from Industrial Polymers,Inc., 3250 South Sam Houston Parkway East, Houston, Tex. 77047. TheHydrospan 100 material generally expands uniformly in all three of itsphysical dimensions as it absorbs water, potentially expanding 60% byvolume. The Hydrospan 100 material belongs to the Polyurethane chemicalfamily, and has a formula maintained as a trade secret of IndustrialPolymers, Inc. However, it is understood to be a reaction product of aPolyether with toluene diisocyanate (TDI).) Other embodiment may use ortypes of materials that also expand and/or contract, or more generallymove, with changing moisture conditions. Some embodiment use compositesthat include the Hydrospan 100 material in combination with otherabsorbent or non-absorbent materials to control or restrict itsexpansion in certain dimensions for example dimensions perpendicular tothe axial dimension of the probe body. Other potential materials includeurethane resins used in diapers, and polymers used to hold and releasewater in soils for plant growing.

As sensor element 140 expands it pushes against plunger head portion 122of indicator rod 120, countering the bias of spring bias element 130.With continued expansion due to persistent presence of moisture insheathing 101, the sensor element will expand enough in size along itsaxial dimension to overcome the spring bias and move the rear portion(drywall end portion) of indicator rod 120 out the rear of the probebody and end cap 150 away from drywall 102, thereby providing a visualindication that a moisture condition has been detected.

End cap 150, in the exemplary embodiment, takes a plastic flange-headform and includes a neck or stem portion 151 bored to engage in aninterference fit with the drywall end portion of indicator rod 120 and aflat head portion 152 integrally formed with stem portion 151. In placeof end cap 150, some embodiments connect the indicator rod to actuate anormally open or normally closed electrical switch. The switch can beelectrically coupled in series with an RFID (radio frequencyidentification) coil to disable or enable an RFID circuit or tocircuitry to trigger an audible or visual alarm or to activate awireless transmitter. In the case of the RFID coil, the switch simplycouples or decouples one node or terminal of the coil from the RFIDchip. Thus, an attempt to read the RFID tag, for example, will indicateeither presence or nonpresence of the tag at the time of the reading.

FIG. 2 shows an end view of probe body 110, with endcap 150 removed forclarity. In this view, an opening 116 through which the elongatedportion 121 of indicator rod 120 can pass is more clearly visible.Opening 116 include four prongs, of which prong 116A is representative.The prong opening allows use of a driver tool, such as the exemplarywingnut-style driver tool 200, shown in FIGS. 3, 4, and 5, to installthe probe assembly such that its end is generally flush with theinterior most surface of drywall 102.

FIG. 6, a center cross-sectional view, shows an exemplary drywall boretool 600 for use in manually boring holes through drywall or sheetrock,with the holes being suitable for installation of a moisture detectionprobe, such as probe assembly 100, as well as for other purposes. Boretool 600 includes a handle portion 610 and a cutting tube 620. Handleportion 610 includes a stem portion 611 which is fixedly mounted, forexample threadly engaged, adhered, or welded, to cutting tube 620.Cutting tube 620, which is made of a durable metal, such as copper,bronze, steel, or aluminum, or a suitable hard and durable polycarbonateor other plastic, includes a sharpened cutting end 621. The end may beformed to include sawtooth teeth in some embodiments.

In use, one positions the cutting end of the tube on the location of adesired hole in sheetrock or drywall and uses the handle to push thetool into the drywall, while turning or reciprocating the handle backand forth, in clockwise and counterclockwise directions, until thecutting tube penetrates the drywall. The tool can then be worked withless effort to cut through insulation, thereby forming an effective borehole or tunnel for installing probe assembly 100, or other suitablepurposes. In the exemplary embodiment, cutting tube 620 forms holesapproximately 0.5 or 0.625 inches in diameter to cooperate with aslightly smaller probe body diameter.

FIG. 7 shows an exemplary moisture detection kit 700. In the exemplaryembodiment, kit 700 includes one or more moisture probe assemblies, suchas probe assembly 100 (or 800 in FIG. 8), one or more bore tools, suchas bore tool 600 or bore tool (1200 in FIG. 12), and one or moreinstallation driver tools, such as wingnut-style driver tool 300.

FIG. 8 shows an exemplary moisture probe assembly 800, which is similarin structure and function to assembly 100 in FIG. 1. The main differencebetween assembly 800 and assembly 100 is the inclusion of a guide tube810.

More specifically, guide tube 810 not only anchors probe body 110′ todrywall 102, but also ensures that it is substantially perpendicularlyto the surface of drywall 102 and sheathing 101, thereby ensuring thatthe sheathing side of sensor element 140 fully contacts surface 101A. Itis believed that deviation from full endface contact of the sensorelement with the monitored surface (surface 101A) will result in lessthan optimal performance of the moisture detection probe assembly, sincemoisture will likely force the sensor element to expand beyondcontainment of the probe body and thereby reduce transfer of axialexpansion force to indicator rod 120. Guide tube 810 (probe guide tube),shown best in FIG. 9, includes a face 811, and two or more, for example3 or 4, leaf-spring prongs 812, and opening 813. Leaf-spring prongs 812,are formed as tapered U-channels with the taper increasing with distanceaway from face plate. Thus, when inserted into a drywall hole and probebody 110′ is passed through opening 813, the probe body spreads theleaf-spring prongs into frictional engagement with the interior surfaceof the drywall hole, anchoring the guide tube in place. The probe bodymay then be pushed flush to sheathing surface ends of the

Other differences between assembly 800 and 100 include an endcap 150′which receives the elongated body portion of indicator rod 120, internallongitudinal ribs 820 (best seen in FIG. 9) within the axial passage ofprobe body 110′, substitution of flattened exterior threads 113A′ onprobe body 110.

FIG. 10 shows an side and perspective views of an altenative guide plate910 which may be used in place of guide tube 810. In contrast to guidetube 810 which includes three leaf-spring prongs of substantiallyequally length, probe guide tube 910 includes two leaf-spring prongs 812and two opposing thread prongs 814A and 814B, which are about half aslong as the leaf-spring prongs and which include respective cleats orprotusions 815A and 815B to better engage with the threads on probe body110′ and thus better ensure the desired perpendicular alignment with thesheathing surface 101A.

FIG. 11 shows a profile view of an alternative exemplary drywall boretool 1100, which is similar in basic function and structure of drywallbore tool 600 in FIG. 6, with the exception of some added features andfor ensure higher precision boring and efficiency. Bore tool 1100includes a handle portion 1110 and a slotted cutting tube 1120, a boreguide plate 1130, and a bore guide ring 1140. Handle portion 1110includes a stem portion 1111 which is fixedly mounted, for examplethreadly engaged, adhered, or welded, to slotted cutting tube 1120.Cutting tube 1120, which is made of a durable metal, such as copper,bronze, steel, or aluminum, or a suitable hard and durable polycarbonateor other plastic, includes a sharpened cutting end 1121 and includes alongitudical slot 1123. The longitudinal slot runs to the top end of thetude to allow full assembly of the tool, though this is not visible inthe figure because of handle stem portion 1111. Bore guide plate 1130includes a bottom face 1131 with protusions 1132 to engage surface ofthe drywall being bored and ensure stable position of the tool duringboring operations. Plate 1130 also includes a guide stem portion 1133with an annular guide ridge 1134. Bore guide ring 1140 includes a slotengagement member 1141 that engages with slot 1123, enabling the boreguide ring to slide freely along the length of the cutting tube betweenthe cutting end and the handle. Bore guide ring 1140 also includes anannular groove 1142 that slideably engages via snap fit with annularguide ridge 1134, defining a lateral rotational plane for the guide ringthat is substantially parallel to bottom face 1131. In operation, a usermanually places the guide plate over the desired bore location andpushes the cutting tube into the drywall surface (generally substratesurface) using the handle. The handle is then worked back and forth, aswith tool 600, with the guide plate and guide ring maintainperpendicular boring through the drywall and beyond.

CONCLUSION

The embodiments described above are intended only to illustrate andteach one or more ways of practicing or implementing the presentinvention, not to restrict its breadth or scope. Nothing presentedherein is intended to be construed as critical, required, or essentialto the invention as claimed. The actual scope of the invention, whichembraces all ways of practicing or implementing the teachings of theinvention, is defined only by the following claims including anyamendments made during pending of the application and all equivalents ofthose claims as issued.

Moreover in this document, relational terms, such as second, top andbottom, and the like may be used solely to distinguish one entity oraction from another entity or action without necessarily requiring orimplying any actual such relationship or order between such entities oractions. The terms “comprises,” “comprising,” “has”, “having,”“includes”, “including,” “contains”, “containing” or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises, has, includes,contains a list of elements does not include only those elements but mayinclude other elements not expressly listed or inherent to such process,method, article, or apparatus. An element proceeded by “comprises a”,“has . . . a”, “includes . . . a”, “contains . . . a” does not, withoutmore constraints, preclude the existence of additional identicalelements in the process, method, article, or apparatus that comprises,has, includes, contains the element. The terms “a” and “an” are definedas one or more unless explicitly stated otherwise herein. The terms“substantially”, “essentially”, “approximately”, “about” or any otherversion thereof, are defined as being close to as understood by one ofordinary skill in the art, and in one non-limiting embodiment the termis defined to be within 10%, in another embodiment within 5%, in anotherembodiment within 1% and in another embodiment within 0.5%. The term“coupled” as used herein is defined as connected, although notnecessarily directly and not necessarily mechanically. A device orstructure that is “configured” in a certain way is configured in atleast that way, but may also be configured in ways that are not listed.

The Abstract of the Disclosure is provided to allow the reader toquickly ascertain the nature of the technical disclosure. It issubmitted with the understanding that it will not be used to interpretor limit the scope or meaning of the claims. In addition, in theforegoing Detailed Description, it can be seen that various features aregrouped together in various embodiments for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter lies in less than allfeatures of a single disclosed embodiment. Thus the following claims arehereby incorporated into the Detailed Description, with each claimstanding on its own as a separately claimed subject matter

What is claimed is:
 1. A moisture detection assembly for use indetecting moisture at a surface of a building structure, the assemblycomprising: a sensor element for contacting the surface of the buildingstructure; an indicator responsive to movement of at least a portion ofthe sensor element to indicate a moisture condition at the surface ofthe building.
 2. The moisture detection assembly of claim 1, wherein thesensor element comprises a water-absorbing polymer which expandsuniformly in at least one of its three physical dimensions as it absorbswater.
 3. The moisture detection assembly of claim 1, wherein the sensorelement consist essentially of a Hydroxy Terminated Poly (Oxyalkylene)Polyol.
 4. The moisture detection assembly of claim 2: wherein thesensor element has the form of a right circular cylinder having a frontface and a rear face; and wherein the assembly further comprises: achamber at least partially containing the sensor element and defining anaxial dimension generally perpendicular to the front face of the sensorelement; means, within the chamber and including a helical spring, forbiasing the front face of the sensor element into contact with thesurface of the building; and wherein the indicator: includes a rodhaving a front portion and rear portion, with the rear portion extendingthrough the helical spring to contact the rear face of the sensorelement, and is responsive to axial movement of the rear face within thechamber to cause the rear portion of the rod to extend outward from thechamber and thereby indicate existence of the moisture condition.
 5. Themoisture detection assembly of claim 4, wherein the chamber comprises acircularly cylindrical plastic (e.g., PVC) tube having a front portionand rear portion and an interior bore therethrough, with the frontportion at least partially containing the sensor element, and the rearportion having an exterior surface including screw threads forengagement with a drywall spaced from the surface.
 6. A method ofdetecting a moisture condition in a building wall having an exteriorsheathing portion and an interior drywall portion, the methodcomprising: placing a water-absorbent material in contact with theexterior sheathing portion; and in response to expansion of thewater-absorbent material, moving an indicator from a first position to asecond position.
 7. The method of claim 6, wherein the water-absorbentmaterial includes a Hydroxy Terminated Poly (Oxyalkylene) Polyol.
 8. Themethod of claim 6, further comprising actuating an electrical switch inresponse to movement of the indicator to the second position; andwherein movement of the indicator to the second position indicates amoisture condition, such as the sheathing having a moisture content ofat least 25%.
 9. A kit comprising: means for creating a hole through adrywall structure and adjacent fiberglass insulation to an exterior wallsheathing of a building; means for passively (i.e., without electricalenergization) detecting a moisture condition in the exterior wallsheathing, wherein at least a portion of the passive detection means issized to fit through the hole and contact the exterior wall sheathing;and means for engaging (e.g., turning) an end portion of the passivedetection means and securing the passive detection means to the drywallstructure.
 10. The kit of claim 9, further comprising a guide tubedelivery system, wherein the guide tube delivery system includes: meansfor insertion into the hole through the drywall structure and forengaging the passive detection means and ensuring substantiallyperpendicular alignment of the passive detection means to the drywallstructure; and means, mounted to the insertion means, for securing asensor end portion of the passive detection means in contact withexterior wall sheathing.
 11. A passive moisture detection system,comprising: a material composition which expands in response to moisturewithin an object it is contacting; and means for indicating thatexpansion of the material composition has occurred.